The hulls of cereal grains have long been recognized as a source of fiber in the diet and have recently been the source of much attention, see J. R. Goldberg, "Jumping on the Bran Wagon", Health, Vol. 18, pp 45 and 46 (June 1986) and "Fiber May Bind Colon Carcinogens", Science News, Vol. 129, p. 43 (Jan. 18, 1986), as a dietary factor in successfully avoiding the occurrence of some cancers.
Refined corn bran products useful as dietary fiber supplements are commercially available, e.g. STALEY.RTM. Refined Corn Bran. Refined corn grain hulls are substantially free of caloric nutrients such as starch and protein and generally are comprised of about 99% insoluble fiber. Soluble dietary fiber is also recognized by some as a source of dietary fiber, see B. Lewis, "Dietary Fiber", Encyclopedia of Chemical Technology, Vol. 7, pp. 628-638 (Kirk-Othmer eds., John Wiley & Sons, Inc. 3d ed., 1979), which may have effects that are different from insoluble dietary fiber.
It would be desirable to produce a dietary fiber supplement from only corn hulls, yet having a ratio of insoluble to soluble fibers that can be varied as desired. However, it is impractical to chemically treat (e.g. degrade) corn hulls to increase the solubility of constituents thereof without significantly changing the functionality of the corn bran.
U.S. Pat. No. 4,565,702 (Morley et al.) discloses a dietary fiber composition prepared by coating an insoluble fiber (e.g. purified corn or wheat bran) with a soluble fiber selected from the group consisting of alginates, gums (e.g. arabic, tragacanth, karaya, ghatti, and seaweed extracts including agar, carrageenan and furcellan), pectin, mucillages (such as psyllium) and similar plant exudates, and mixtures thereof.
European Patent Publication No. 190826, published Aug. 13, 1986 on E.P.O. Application No. 86300236.6, filed Jan. 15, 1986, discloses an ingestible aggregate comprising a pre-swelled substantially anhydrous hydrocolloid and a substrate. Hemicellulose is listed only as an example of a substrate. The aggregates are prepared by contacting the substrate with an aqueous solution of the hydrocolloid to form aggregates and then drying and collecting the aggregates.